Answer:
<em>Oxygen has 8 protons in the nucleus while nitrogen only has 7. A bonding pair will experience more attraction from the oxygen's nucleus than from nitrogen's, and so the electronegativity of oxygen is greater.</em>
Nucleus of the atom, that contains protons and neutrons.
I would say that there is 270 grams left. since its F2 you have three things there.
divide 405 by 3
you will get 135.
but there are 2 F's so multiply that by 2 and you will get 270.
the final answer should be 270 grams left.
A Covalent bond forms when two or more atoms share electrons in a chemical bond